<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>CSS 学习第四天</title>
    <style>
        .box {
            width: 100px;
            height: 100px;
            background-color: pink;
            margin: 20px auto;
            box-shadow: 10px 10px 5px 5px black;
            border-radius: 50px;
        }
    </style>
</head>
<body>
<div class="box">

</div>
</body>
</html>